1. The Top Quark Discovery
Mike Strauss
The University of Oklahoma

2. CDF DØ

3. DØ Detector
It’s a big camera that takes pictures of particle collisions

4. DØ Detector Multiple components with different functions
Weighs 5000 tons
Inspect 3,000,000 collisions/second
Records 50 collisions/second
30’
30’
50’

5. Electromagnetic Calorimeter (e and g)
Muon (m) chambers
Charged particle tracks
Neutrinos? pT  0

6. How quarks usually interact in the detector
Remember that quarks are always confined!
Hadronization q
As quarks leave a collision, they change into a ‘shotgun blast’ of particles called a ‘jet’ q 

7. Top Quark Production and Decay

8. Top Decay Modes Top quark events are characterized by their decay mode
44%
15% 5%
15%

9. An event in the DØ Detector that looks like a top quark

10. Another Top Quark Candidate Event

11. Count the number of top quark candidates and compare with a computer simulation
mt  175 GeV